A machine that converts mechanical energy into electrical energy is called a generator, alternator or dynamo. The general physical principle underlying the operation of a generator is that of electromagnetic induction. If a conductor is moved through a magnetic field, a current is set up or induced in the conductor.
A generator, or alternator, consists of two basic units, the field, which is the electromagnet with its coils, and the armature, the structure that supports the conductors which cut the magnetic field and carry the induced current in a generator. The armature is usually a laminated soft iron core around which conducting wires are wound in coils. A simple generator will produce an electric current that alternates in direction as the armature revolves. It is often desirable to generate as high a voltage as possible, and rotating armatures are not practical in such applications because of the possibility of sparking between brushes and slip rings, and the danger of mechanical failures that might cause short circuits. Alternators are therefore conventionally constructed with a stationary armature within which revolves a rotor composed of a number of magnets. In such a case, the magnetic field is in motion, rather than the conductors of the armature.
The current generated by conventional alternators rises to a peak, sinks to zero, drops to a negative peak, and rises again to zero a number of times each second, depending on the frequency for which the machine is designed. Such current is known as single phase alternating current. If, however, the armature is composed of two windings, mounted at right angles to each other, and provided with separate external connections, two current waves will be produced, each of which will be at its maximum when the other is at zero. Such current is called two-phase alternating current. If three armature windings are utilized, current will be produced in the form of a triple wave, known as three-phase alternating current. A larger number of phases may be obtained by increasing the number of windings in the armature.
Conventional alternators, as described above, are utilized in a wide variety of industry to produce electrical power. However, such alternators are limited in use by their weight and size.
It is therefore a general object of the present invention to provide an improved alternator which will produce a greater amount of electricity than a conventional alternator of the same size.
Another object of the present invention is to provide an improved alternator which is capable of producing a variety of voltages simultaneously.
A further object is to provide an alternator which is capable of producing a single voltage larger than that of conventional alternators of similar weight and size.
These and other objects of the present invention will be apparent to those skilled in the art.